Antioxidant, Anticancer and Antimicrobial, Effects of Rubia cordifolia Aqueous Root Extract

Aims: To evaluate the total antioxidant capacity (TAC) of Rubia cordifolia root extracts, to test anticancer activity against MDA-MB-231 breast cancer cell lines, and to evaluate antimicrobial activity of the same extract versus six Gram-positive and negative bacteria.

Study Design: In vitro.

Place of Study and Duration: School of Biomedical Sciences, Ulster University, July 2014-Sept 2015.

Methodology: TAC was tested using ABTS, DPPH, FRAP and Folin assays and values were expressed as mg-gallic acid equivalents per 100 g (GAE/100 g) of sample. Anticancer properties were examined against MDA-MB-231 breast cancer cell lines using Sulforhodamine B assay. Antimicrobial activity was examined using a disk diffusion assay with three Gram-positive (Staphylococcus epidermidis, Staphylococcus aureus and Bacillus cereus) and three Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi) bacteria.

Results: TAC of dry extracts of Rubia cordifolia ranged from 523±43 to 4513±208 (mg GAE mg/100 g) depending on the method of analysis, ABTS> FRAP> Folin > DPPH methods. R. cordifolia dry extract showed cytotoxicity against MDA-MB-231 with IC50 = 44 µg/ml or 5.1µM GAE. No antimicrobial activity was observed against the three Gram-positive, or three Gram-negative bacterial species using the water extract or R. cordifolia.

Conclusion: R. cordifolia aqueous extract possess high total antioxidant capacity but values depend on the method of analysis. R. cordifolia extract inhibits MDA-MB-231 breast cancer cells proliferation but nil anti-bacterial activity was observed for three Gram-positive and three Gram-negative bacterial strains tested.